Phys.org November 1, 2024 The guiding and transport of energy, for example, of electromagnetic waves, underpins many modern technologies, ranging from long-distance optical fibre telecommunications to on-chip optical processors. It requires localizing the waves or particles in the confinement region, such as total internal reflection at a boundary. An international team of researchers (UK, USA – University of Arizona) introduced a waveguiding mechanism that relies on a different origin for the exponential confinement and that arises owing to the physics of diffusion. They demonstrated this concept using light and showed that the photon density could propagate as a guided mode […]
Category Archives: Photonics
Omnidirectional color wavelength tuning method unlocks new possibilities for smart photonics
Phys.org May 22, 2024 Ideally, on-demand omnidirectional wavelength control is highly desirable from the perspective of wavelength-tuning freedom. However, despite numerous previous research efforts on tunable chiral liquid crystals (CLCs) structural colors, only mono-directional wavelength tuning toward shorter wavelengths has been employed in most studies to date. Researchers in South Korea demonstrated the ideally desired omnidirectional wavelength control toward longer and shorter wavelengths with significantly improved tunability over a broadband wavelength range. They achieved simultaneous and omnidirectional structural color-tuning control by using areal expanding and contractive strain control of dielectric elastomer actuators (DEAs) with chiral liquid crystal elastomers (CLCEs). According […]
Key innovation in photonic components could transform supercomputing technology
Phys.org February 5, 2024 Researchers in South Korea demonstrated the array-level tunable couplers and phase shifters with capacitive electrostatic microelectromechanical actuators in a recirculating mesh network. The overall fabrication process was compatible with the conventional wafer-level passive silicon photonics platform. Extremely low unit-level standby power consumption of and reconfiguration energy with <11 V programming voltages offered well-balanced, scalable routes for efficient phase and amplitude modulation of the guided lightwaves with sub-decibel optical losses. The extinction ratios of the continuously tunable directional coupler exceed 30 dB. Full 2π-phase shifting could be achieved with a modulation efficiency of less than 0.075 V cm and a phase-dependent […]
New technique for photon detection
Science Daily December 12, 2023 Currently, all available detectors for detecting long wave infrared (LWIR) light at room temperature operate on amplitude modulation (AM) and are limited in performance by AM noises, including Johnson noise, shot noise, and background fluctuation noise. Researchers at the University of Central Florida have introduced a frequency modulation (FM)-based detection technique , which offers inherent robustness against different types of AM noises. The FM-based approach yields an outstanding room temperature noise equivalent power (NEP), response time, and detectivity (D*). According to the researchers this result promises a novel uncooled LWIR detection scheme that is highly […]
A first-of-its-kind chip features both a laser and waveguide to create a photonic integrated circuit
Phys.org August 9, 2023 To replace bulk optics and fibres in high-precision and highly coherent applications, ultralow-noise laser sources integrated with other photonic components in a compact and robustly aligned on a single chip are preferred. However, there are two major issues preventing the realization of such photonic integrated circuits: the high phase noise of semiconductor lasers and the difficulty of integrating optical isolators directly on-chip. An international team of researchers (USA – UC Santa Barbara, Caltech, industry, Egypt) leveraged three-dimensional integration that resulted in ultralow-noise lasers with isolator-free operation for silicon photonics. Through multiple monolithic and heterogeneous processing sequences, […]
Revolutionizing optical control with topological edge states
Phys.org June 6, 2023 It is highly desirable to be able to control topological edge states (TES) transport in photonic implementations. Enhancing the coupling between the TESs in a finite-size optical lattice can exchange light energy between the boundaries of a topological lattice, hence facilitating the flexible control of TES transport. However, existing strategies have paid little attention to enhancing the coupling effects between the TESs through the finite-size effect. Researchers in China established a bridge linking the interaction between the TESs in a finite-size optical lattice using the Landau–Zener model to provide an alternative way to modulate/control the transport […]
Researchers use structured light on a chip in another photonics breakthrough
Phys.org May 17, 2023 Despite recent demonstrations of various topological photonic phases, the full potential offered by Dirac photonic systems, specifically their ability to emulate the spin degree of freedom—referred to as pseudo-spin—beyond topological boundary modes has remained underexplored. An international team of researcher (USA – City College of New York, AFRL (Eglin AFB), Australia) showed an example of relativistic-like trapping in photonic system that realizes Dirac-like dispersion with spatially inhomogeneous mass term. The modes trapped by such cavities, their energy levels, and corresponding orbitals were characterized through optical imaging in real and momentum space. The fabricated cavities hosted a […]
Quantum light source goes fully on-chip, bringing scalability to the quantum cloud
Nanowerk April 17, 2023 The quantum light sources developed so far have relied on external bulky excitation lasers, making them impractical prototype devices that are not reproducible, hindering their scalability and transfer out of the laboratory into real-world applications. An international team of researchers (Germany, the Netherlands) demonstrated a fully integrated quantum light source that overcame these challenges through the integration of a laser cavity, a highly efficient tunable noise suppression filter and a nonlinear microring for entangled photon-pair generation through spontaneous four-wave mixing. The hybrid quantum source employed an electrically pumped InP gain section and a Si3N4 low-loss microring […]
A new type of photonic time crystal gives light a boost
Phys.org April 5, 2023 The synthesis of photonic time crystals materials and experimental observation of their physics remain very challenging because of the stringent requirement for uniform modulation of material properties in volumetric samples. An international team of researchers (Finland, Germany, USA – Stanford University) has extended the concept of photonic time crystals to two-dimensional metasurfaces. They demonstrated that time-varying metasurfaces not only preserve key physical properties of volumetric photonic time crystals despite their simpler topology but also host common momentum bandgaps shared by both surface and free-space electromagnetic waves. Based on a microwave metasurface design, they experimentally confirmed the […]
Team develops silicon photonic MEMS compatible with semiconductor manufacturing
Phys.org March 22, 2023 Silicon’s relatively weak electro-optic effects result in modulators with a significant footprint and thermo-optic tuning devices that require high power consumption, which are substantial impediments for very large-scale integration in silicon photonics. An international team of researchers (Switzerland, Sweden, Belgium, Ireland) has introduced a silicon photonic MEMS platform consisting of high-performance nano-opto-electromechanical devices fully integrated alongside standard silicon photonics foundry components, with wafer-level sealing for long-term reliability, flip-chip bonding to redistribution interposers, and fibre-array attachment for high port count optical and electrical interfacing. Their experimental demonstration of fundamental silicon photonic MEMS circuit elements, including power couplers, […]